Bloodstream Infection + Sepsis

Question 1

What is sepsis?

Answer 1

a life-threatening condition that arises when the body’s response to infection causes injury to its own tissues and organs.

microbial invasion + systemic inflammation = resulting in organ dysfunction

Question 2

Name some of the risk factors involved in sepsis?

Answer 2

1. underlying malignancy
2. age over 65
3. immunocompromised
4. alcoholism

Question 3

Name some of the key diagnostic features of sepsis /evidence of systemic inflammatory response (SIR) ?

Answer 3

SIR = 2+ of the following

1. Temp: over 38 or under 36
2. Resp rate: over 20/min (tachypnoea)
3. Heart rate: over 90/min (tachycardia)
4. Very high or very low WBC
5. Neutropenia

Question 4

What is the difference between bacteraemia and septicaemia?

Answer 4

bacteraemia = the presence of bacteria in the bloodstream. terminated by host immune system.

septicaemia = bacteraemia + sepsis

Question 5

Summarise the pathogenesis of sepsis?

Answer 5

Bacteria in bloodstream release toxins, which trigger an immune response and activate a cytokine cascade leading to physiological effects.

Question 6

Name some of the resulting effects of the cytokine cascade?

Answer 6

1. clotting activation
2. activation of the autonomic nervous system
3. oxidative stress
4. increased endothelial permeability

Question 7

what is the effect of increased endothelial permeability?

Answer 7

• designed to enable the release of cells and tissue fluid to the site of infection
• an increase can lead to distributive shock!
• with infection, HR and cardiac output increase but the combination of vasodilatation and endothelial permeability means that the body struggles to maintain BP
• the decrease in BP forces the body to peripherally shut down as blood is re-directed to key organs

Question 8

Name some common causes of community-onset sepsis?

Answer 8

1. UTI
2. Pneumonia
3. Meningitis
4. Infective endocarditis

Question 9

What is infective endocarditis?

Answer 9

infection established on heart valves, can result in severe infection as bacteria is constantly ‘showered’ into the bloodstream

Question 10

Name some of the risk factors for developing endocarditis?

Answer 10

1. Previous valvular disease
2. Prosthetic valve
3. IV drug use
4. Central lines
5. Previous history of rheumatic fever as a child?

Question 11

Name some of the common organisms responsible for endocarditis?

Answer 11

1. Streptococci (s. pyogenes) — often in the elderly, ?history of valvular problem, rheumatic fever as a child for e.g.
2. S. aureus — often seen in IV drug users

Question 12

What is rheumatic fever?

Answer 12

inflammatory response to strep infection of the throat (s. pyogenes) antibodies can react against the myocardium and joints to produce symptoms
(repeated attacks - valvular disease)

Question 13

Name some of the common causes of hospital onset sepsis?

Answer 13

1. Lines
2. Urinary catheters
3. VAP
4. Post op wound infections

Question 14

Name some of the “red flag” symptoms for high risk sepsis?

Answer 14

1. Newly altered mental state
2. Very high RR (over 25)
3. Very high HR (over 130)
4. Very low systolic pressure (less than 90)
5. Low urine output
6. Non-blanching rash
7. Mottled appearance: cyanosis of the skin, lips and tongue

Question 15

What are the steps of “sepsis 6” resuscitation bundle?

Answer 15

1. Oxygen!
2. Do blood cultures
3. Serum lactate
4. IV antibiotics within 1hr
5. Fluids IN and OUT
6. Urgent senior review and consider critical care